It analyzed the largest bank holding companies in terms of total assets according to the National Information Center, a repository of financial data and institution characteristics collected by the Federal Reserve System.

FORBES: The 15 Best-Paying Big Banks

We only assessed the 20 largest bank holding companies in terms of total assets, as of December 2012, according to the National Information Center, a repository of financial data and institution characteristics collected by the Federal Reserve System.

FORBES: The Big Banks Hiring The Most Right Now

The virtual reconstruction of Implenia's data center pulled information about the layout of servers and storage, the devices' temperatures, power consumption and data processing over the Internet to IBM's servers, where they were built into a 3-D virtual world model.

FORBES: Breakthroughs